Curanex Achieves Key Preclinical Milestone with Favorable Toxicology Profile at Maximum Dose, Advancing Toward IND Submission

Phyto-N 28-Day Repeat-Dose Study in Rats and Dogs Shows No Findings of Toxicological Significance at Maximum Feasible Dose, Enabling Advancement to GLP Toxicology Program

Jericho, New York, March 18, 2026 (GLOBE NEWSWIRE) -- Curanex Pharmaceuticals, Inc. (Nasdaq: CURX) (“Curanex” or the “Company”), a development-stage pharmaceutical company focused on the discovery and development of botanical drugs for inflammatory diseases, today announced the successful completion of a dose-range finding toxicology study of its lead botanical drug candidate, Phyto-N, conducted in Sprague-Dawley rats and dogs. The study evaluated repeat-dose oral tolerability over 28 days and is designed to inform dose selection and study design for the Company’s subsequent Good Laboratory Practice (GLP)-compliant toxicology studies required for its planned Investigational New Drug (IND) application, which the Company targets to submit in the fourth quarter of 2026.

Phyto-N has an established human use history in China spanning more than 30 years, having been administered at a daily dose of 30 g for the treatment of inflammatory diseases in thousands of patients, with a favorable tolerability profile. To bring Phyto-N into clinical development in the United States, the Company is conducting the full suite of nonclinical studies required by the FDA to support an IND application, including GLP toxicology, pharmacokinetics, and Chemistry, Manufacturing and Controls (CMC) work. The Company views this rigorous, systematic approach as the appropriate foundation for a robust regulatory filing and, ultimately, for a successful clinical program.

Phyto-N was administered twice daily by oral gavage for 28 consecutive days across multiple dose levels in both rats and dogs. In each species, the maximum feasible dose (MFD) was established based on the maximum achievable drug concentration and the maximum daily gavage volume. The highest dose tested was approximately six times the proposed clinical oral dose in dogs and approximately four times in rats.

All animals underwent comprehensive safety assessments throughout the study period, including hematology, coagulation parameters, serum biochemistry, and gross and histopathological examination of major organs. No treatment-related adverse findings of toxicological significance were observed at any dose level in either species.

These results are consistent with Phyto-N’s safety profile accumulated over more than 30 years of human use in China, and provide a sound scientific basis for proceeding to the formal GLP toxicology program. The MFD identified in this study will serve as the high-dose anchor for the design of the pivotal GLP studies that will form a core component of the Company’s IND submission.

“The completion of this toxicology study, which demonstrated an acceptable safety profile at the maximum feasible dose, is an important and encouraging milestone for Phyto-N,” said Jun Liu, Chief Executive Officer of Curanex. “This result, taken together with more than 30 years of prior human use experience from China, gives us strong confidence in the safety foundation of this program. We are now firmly on the path toward our IND submission, and we look forward to sharing further progress as we advance through the remaining nonclinical milestones.”

“This dose-range finding study was specifically designed to generate the data needed to optimize the design of our upcoming GLP toxicology studies—a critical step in the FDA-required nonclinical package,” said Liqin Xie, Ph.D., Chief Operating Officer of Curanex. “The results, with no findings of toxicological significance across both species, streamline our path forward and keep us on schedule toward our target IND filing timeline.”

Phyto-N is Curanex’s lead botanical drug candidate in preclinical development for inflammatory diseases, with moderate-to-severe ulcerative colitis (UC) as the primary indication. UC is a chronic inflammatory bowel disease affecting approximately 5 million patients worldwide and representing a significant unmet medical need.

Phyto-N is a botanical extract derived from a single plant species with demonstrated anti-inflammatory properties, acting through multiple targets and mechanisms. The Company has evaluated Phyto-N’s activity in multiple inflammatory disease animal models. Phyto-N has been used in China for more than 30 years in thousands of patients with inflammatory diseases, demonstrating a favorable tolerability profile. The Company is advancing Phyto-N through FDA-required nonclinical studies toward an IND submission targeted for the United States in the fourth quarter of 2026, with Phase 1 clinical development planned to initiate in Australia in the fourth quarter of 2026, in each case subject to the completion of required studies and regulatory clearance.

Curanex Pharmaceuticals Inc is a development-stage pharmaceutical company headquartered in Jericho, New York, dedicated to discovering and developing botanical drugs for inflammatory diseases. Its lead candidate, Phyto-N, is a botanical extract from a single plant with demonstrated anti-inflammatory properties that acts via multiple targets and mechanisms. Phyto-N has a well-established human use history, having been administered to thousands of patients with inflammatory diseases for more than 30 years in China, demonstrating favorable tolerability. The Company has validated Phyto-N's effects in animal models of six inflammatory diseases: ulcerative colitis, atopic dermatitis, COVID-19, diabetes, nonalcoholic fatty liver disease, and gout. The Company’s primary development focus is moderate-to-severe ulcerative colitis. Phyto-N is currently advancing through FDA-required nonclinical studies in preparation for a U.S. IND submission targeted for the fourth quarter of 2026. Phase 1 clinical development is planned to initiate in Australia in the fourth quarter of 2026, in each case subject to the completion of required studies and regulatory clearance.